1. Field of the Invention
The invention relates generally to apparatus for acquiring data for analysis and control, and more specifically to a data processing system for collecting data in the form of analog or digital signals, digitizing the signals as necessary and analyzing the digitized data.
2. Description of the Prior Art
Data acquisition systems may be coupled to sensing and other input devices by signal lines, some providing analog signals, and others, digital signals. The amplitudes and/or frequencies of the analog signals may be sampled at a predetermined rate to generate a digital representation at the times of sampling. The digital signals may also be sampled at a predetermined rate or may be processed in real time. The amplitudes of analog signals may, for example, represent temperature, pressure, velocity or even light intensity. The frequencies of the analog signals may, for example, represent vibration.
A typical data acquisition system may sample and analyze such signals for a number of reasons. The system may monitor the temperature of a chemical reaction to determine if safe limits are being exceeded or if the next stage of a process should be initiated. The system may monitor the change in velocity of a test crash vehicle to gather data to design a better bumper. The system may monitor the frequency of vibrations of a machine to anticipate failure. The system may monitor temperature and humidity in a factory to keep such conditions within certain prescribed limits. Or, the system may measure how light intensity varies with time when testing a flash bulb. The latter information could be used to compare various designs of flash bulbs.
Prior art systems are capable of collecting data at high sampling rates and offer high resolution. However, these systems typically require highly skilled operators to set up the systems for data collection and analysis, since the systems generally must be programmed for each job individually. The operators must also keep track of test setups, data and analysis functions being performed. A further problem with prior art systems is that it is generally difficult to change parameters on the fly when performing a particular test.